Selectable lethality yield inflatable grenade

Abstract

A selectable yield fragmentation grenade is provided with a feature for relatively easily setting the output of the grenade to a higher or to a lower yield lethality output of fragments. An operator can selectively inflate the grenade by various provisions, and such inflation lowers the grenade's lethality yield output.

Claims

1. A selectable yield fragmentation grenade, comprising an elastomeric outer body, wherein said outer body includes fragments in a circumferential fragmentation belt, said grenade having an inside main detonation charge and means to initiate detonation of said main charge, and whereby said grenade may be exploded to lethally generate fragments by detonating said main charge, and wherein the circumferential fragmentation belt further includes propellant in a pocket band, and the grenade further includes means for selectively firing such propellant.

2. The grenade of claim 1, wherein the grenade may be selectively fully inflated by igniting said propellant before said grenade main charge is detonated, and such prior full inflation of the grenade will result in selection of a low lethal yield fragmentation pattern for the grenade upon its explosion.

Description

LIST OF DRAWINGS

(1) FIG. 1 shows a top cross sectional view of an inflatable grenade according to this invention.

(2) FIG. 2 shows a front view of the inflatable grenade according to this invention.

(3) FIG. 3 shows a top cross sectional view of the inflatable grenade, in an inflated state according to this invention.

(4) FIG. 4 shows a top cross sectional view of the inflatable grenade, in its non-inflated state according to this invention.

DETAILED DESCRIPTION

(5) A fragmentation case is provided in this invention comprising a multiplicity of preformed fragments deposited into an elastomeric material matrix in a closed elastic material type grenade device. Elastometric materials might include rubber, plastic, metallic, composites or other materials. Fragments may be of tungsten alloy, steel, or any other hard high-density materials. The fragments may be molded, casted, or over molded in place in the belt and may be fixed in place in the belt by a filler material like plastic, rubber, composites, epoxies, urethanes, etc. The fragments may be a variety of shapes, sizes, materials, such as balls, cubes, or nearly any shape including star shaped, etc as dictated by the particular application, or a mixture of such shapes. A selectable yield output is achieved by expanding the grenade device. Expansion of the elastomeric fragmentation case may be accomplished by a liquid gas or by a propellant gas generator activated prior to detonating the main charge explosive which may comprise high explosives such as TNT and/or HDX/RDX or any commonly used high explosive compositions. In the less lethal mode, before detonating a main charge explosive the fragmentation case may be rapidly expanded by disbursing liquid gas (such as CO2, He, H2, or the like) from a relatively tiny storage cartridge included with the grenade device until the elastomeric matrix ruptures, propelling fragments away from the inner main charge explosive, and just before the final detonation of such inner explosive. Using light weight combustible gases such as H2, will increase non-lethal stunt effect by producing additional blast and light. This mode causes less lethality than if detonating the grenade without first expanding it with gas. Alternatively, detonation could be done at some longer time after adding the gas if desired. The expanded grenade device could have a diameter three times that of a non-inflated grenade device. As mentioned, a multiplicity of preformed fragments are deposited into an elastomeric material matrix. The fragmentation case has the capability of sustaining predetermined dilation to provide prescribed separation gap between the main explosive and the fragments, if desired. The shape of the warhead or grenade can be spherical, cylindrical, or complex, however, prescribing the extent of the air or gas-filled gap between the explosive and the fragmentation case will determine the amount of momentum transferred from the explosive detonation products to that of the fragments. Therefore such gap size also then dictates resulting fragment velocities, and thus grenade lethality. As was mentioned, in a full lethality mode, there is no dilation applied; the fragmentation case is in close contact with the main explosive, yielding maximum fragment velocities. In a less lethal mode, before detonating the explosive, the fragmentation case is expanded (rapidly as desired) until the elastomeric matrix raptures, propelling fragments away from the explosive. Then, approximately the entire momentum of the explosive detonation products will be deposited into the air-blast, yielding a little or no lethality in the fragments. In a partial yield mode, the grenade lethality yield may be controlled by the extent of the gap between the explosive and the (partially dilated) fragmentation case. By way of example, in FIG. 1, a grenade 100 (top cross-sectional view) has an outer elastomeric fragmentation case liner 109 which also encloses an inner main explosive charge 106. The area 104 in between 106 and 109 is normally not filled with added gas. The grenade also has means 111 to detonate said main explosive charge 106 along line 112. In a cross-sectional view normal to the surface of the fragmentation case 109, FIG. 2, fragments 210 are embedded in an elastomeric matrix 207. For a low fragment yield operation, valve 103 may be used to permit gas from connected unit gas source 115 to be added to the grenade, inside the case liner 109. A suitable gas should probably be inert for safety concerns against unwanted burning, and not of a more toxic or poisonous variety if possible. Only after inflating the grenade, the main explosive charge 106 would then be initiated. Cross-sectional view FIG. 3 illustrates an inflated grenade, including gas in inflated area 304, prior to detonation of main explosive charge 106, whereas cross-sectional view FIG. 4 illustrates a non-inflated grenade with no gas added in area 104, prior to detonation of main explosive charge 106. According to an alternative method, (see FIG. 2), dilation of the fragmentation case may be accomplished by a thin layer of propellant deposited between the explosive and the case, initiated at a predetermined time before detonating the main explosive charge. In such alternate method for inflating, an elastomeric pocket band 204 may be included to contain a small supply of propellant. And, the grenade includes means 215 to ignite said propellant along line 217 which means may include a fuze. A circuit switching means 216 (not completely detailed) may be included to control the timing of detonation of 111 and 215. Such propellant would then be activated first and cause inflating of the grenade by the releasing gas created by the propellant burn, before detonating the main explosive charge 106. In both methods of inflating the grenade prior to detonation, a selectable partial yield output may be accomplished if desired, determined by the time delay between activating the case expansion, and when detonating the main explosive charge.

(6) While the invention may have been described with reference to certain embodiments, numerous changes, alterations and modifications to the described embodiments are possible without departing from the spirit and scope of the invention as defined in the appended claims, and equivalents thereof.